Boat support for trailers

ABSTRACT

A boat support designed to accommodate changes in the load distribution on a boat trailer. Self-balancing hull support roller assemblies are combined on a supporting framework together with a bow securing assembly. Limited movement is provided on the framework between the bow securing assembly and the hull supporting assembly to permit self-balancing of the hull supporting assembly independently of the bow securing assembly. Such movement can be provided by a limited pivotal connection between the trailer framework and tongue of the trailer, by walking beam supports for multiple hull supporting assemblies or by an arrangement which allows limited elevational movement of the bow securing assembly relative to the trailer framework.

llam E59 BOAT SUPPORT FOR TRAILERS [75] Inventor: Oscar C. Calkins,Spokane, Wash.

[73] Assignee: Calkins Manufacturing Company, Spokane, Wash.

22 Filed: .lan.3,1972

211 Appl. No.: 214,713

I FOREIGN PATENTS OR APPLICATIONS 655,970 5/1965 Belgium 280/414 RPrimary ExaminerLeo F riaglia Attorney Wells, St John & Roberts [57]ABSTRACT A boat support designed to accommodate changes in the loaddistribution on a boat trailer. Self-balancing hull support rollerassemblies are combined on a supporting framework together with a bowsecuring assembly. Limited movement is provided on the framework betweenthe bow securing assembly and the hull supporting assembly to permitself-balancing of the hull supporting assembly independently of the bowsecuring assembly. Such movement can be provided by a limited pivotalconnection between the trailer framework and tongue of the trailer, bywalking beam supports for multiple hull supporting assemblies or by anarrangement which allows limited elevational movement of the bowsecuring assembly relative to the trailer framework.

PATENIE JAN 1 51,974

SHEU 2 0F 5 BACKGROUND OF THE INVENTION This disclosure relates to animprovement in the type of boat trailer illustrated by the disclosure inUS. Pat. No. 3,512,667, granted Apr. 21, 1969. The boat trailer includesself-centering or self-balancing cradle assemblies for hull engagement.Each cradle assembly is pivoted to the trailer framework about atransverse axis intermediate front and rear rollers that engage andcarry the weight of a portion of the boat hull. In the patenteddisclosure, weight of the boat is balanced between the rollers on eachcradle assembly, but two or more cradle assemblies are normally requiredto support a boat of any substantial size, and heretofore rigid frameconnections have been utilized between these multiple cradle assemblies.

In the use of such a trailer, the bow of the boat is normally fixed toan upright mast at the tongue or front of the trailer, typically througha locked winch and cable or rope. The transom of the boat is normallytied down at the rear cradle assembly. The various hull supports in theform of rollers, pads, bunks, etc., are located along the framework toachieve desired weight distribution for the boat hull while stationaryon the trailer in a loaded condition. They can be pre-adjusted for aparticular boat. However, as the trailer is used for road travel, minormomentary adjustment of the loading arrangement is inevitable due tovertical movement of the wheels as caused by road or surface variations.Upward or downward movement of the wheels is transmitted to theframework, causing momentary deflection of the framework and resultingload variations on the various devices in contact with the boat hull.Assuming that the hull itself is rigid, deflection of the trailerframework causes some rollers to exert considerable increases in forceon the boat trailer surfaces, while other rollers might momentarily beentirely free or disengaged from the boat. surfaces. In practice, thishas resulted in wear at the exterior boat surfaces, a conditionparticularly troublesome in the case of reinforced plastic boathulls,where the outer plastic material or gel coat is often worn completely inthe area of roller contact.

Another problem of load variation along a boat trailer arises from thenature and use of a boat trailer, particularly when carrying a pleasureboat. It frequently occurs that the boat user will utilize the boatitself to transport spare boat motors, ice chests, camping equipment andother various portable materials. The weight variation and distributionalong the trailer can vary considerably from that for which the traileris designed or pre-adjusted. This often creates serious imbalances inthe loading of the boat trailer when at rest, and even furtheraccentuates the problems of road shocks during travel while so loaded.

The solution to these problems, as disclosed in detail in the followingdescription, is to provide essentially two point support of the boat inthe loaded or travel condition on the boat trailer by a hull supportingassembly and a bow engaging assembly, and to permit limited elevationalvariation between these assemblies independently of one another. Thisrequires a self balancing hull support assembly capable of engaging thehull along its horizontal lenth. The hull support can be of the typeshown in US. Pat. No. 3,512,667 or altemate hull supports which areself-balancing about an intermediate fulcrum on the trailer framework soas to automatically distribute the load between longitudinally spacedrollers or other hull engaging members. With this improved arrangement,momentary road shocks and variations in static load are accommodated bythe limited movement permitted between the two assemblies on the boattrailer.

SUMMARY OF THE INVENTION The invention relates to a boat trailer havinga wheelsupported framework, bow securing means mounted to the framework,hull support means mounted to the framework and movable connecting meanson the framework between the hull support means and the bow securingmeans for permitting automatic selfbalancing of the hull support meansduring road travel independently of the bow securing means.

It is a first object of this invention to provide an improved boattrailer configuration capable of absorbing and controlling theapplication of varying static boat loading or momentary vertical loadingon the trailer framework due to road shocks or surface conditions onwhich the trailer is traveling.

Another object of this invention is to provide several specific devicesfor accommodating load variation in forms applicable to most existingtypes of boat trailers.

Another object of this invention is to provide such an improvement in amanner that does not necessarily add materially to the cost of the boattrailer and which can be utilized at an added cost readily justifiableby the resulting decrease in trailer damage or boat hull damage duringuse of the trailer.

These and further objects will be evident from the following disclosure,which sets out three specific forms of the basic invention. Thesespecific forms are presented by way of illustration and other obviousadaptations of the concepts disclosed herein will be readily observableby those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 7 is a side elevation view of thetrailer shown in FIG. 6;

FIG. 8 is a plan view of the third form of the invention;

FIG. 9 is a side elevation view of the trailer shown in FIG. 8;

FIG. II) is a perspective view showing the bow securing assembly ofFIGS. 8 and 9 at an enlarged scale; and

FIG. 11 is a top view of the bow securing assembly shown in FIG. 10,with the general outline of a boat bow illustrated in dashed lines.

DESCRIPTION OF THE PREFERRED EMBODIMENTS GENERAL DESCRIPTION FIGS. 1-3schematically illustrate three arrangements by which one can utilize thepresent improvement in the design of a boat trailer. The followinggeneral description applies to these three illustrative structures,which are shown in detail in the remaining drawings. The referencenumerals in this general description are common to all schematic anddetailed forms of the disclosure, except in those instances which arespecifically denoted with respect to a specific embodiment.

The trailer comprises a main structural framework designated by thenumeral 10. Framework includes a forward longitudinal tongue 11 and rearside members 12 which extend longitudinally along the boat hull 26 atthe respective sides thereof. Framework 10 is typically supported by atransverse wheel assembly 13 2 which includes one or more pairs ofground engaging wheels.

At the front of tongue 11 is a bow securing assembly 14. It includes awinch 15 having a cable releasably attached to the bow of the boat hull26. The cable and winch 15, when secured, hold the bow of the boat in afixed position against a bow bracket 16 located at the upper end of amast 17.

The hull supporting assemblies 18 are in the form of multiple pairs ofrollers, 22, 23, mounted at opposite longitudinal ends of individualsupport frames 20, each frame 20 being pivotally supported intermediatethe rollers 22, 23 at pivot connections shown at 24. Because of thisintermediate pivotal support, the load on the paired rollers 22, 23 isautomatically balanced to attain a working static condition. The pivotalsupport of the rearmost frame 20 is further utilized to assist inloading and unloading of the boat hull 26 with respect to the trailer.The details of construction and use of self-centering or self-balancingroller supports of this general type are set out in US. Pat. No.3,512,667, which is herein incorporated by reference.

To accommodate change in the loading applied to the trailer framework 10during road travel and to eliminate the usual resulting excessive wearon the exterior surfaces of boat hull 26 caused by the rollers 22, 23 orother hull engaging devices, provision is made herein for automaticself-balancing of the hull engaging assembly 18 independently of the bowsecuring assembly 14.

As shown in FIG. 1, this is achieved by pyramiding the frames 20 ontransversely pivoted longitudinal frames 27 and ultimately supportingthem upon a main walking beam 28 at each side of the boat trailer. Eachwalking beam 28 is pivoted to the side members 12 of framework 10 atpivot connection 30. Thus, automatic load equalization orreapportionment is achieved between all of the paired rollers 22, 23along the full length of the boat hull 26, and frame deflection orloading will be distributed through all of these rollers, and notconcentrated at any particular roller, nor will any roller bemomentarily freed from loading due to such deflection.

In FIG. 2, the hull supporting assembly is not mounted to the sidemembers 12 at a single axis, but at two pivot connections 36 at oppositesides of the wheel assembly 13. The tongue 11 is not rigidly connectedto the side members 12, but is pivoted to them about a transverse pivotconnection 33, which permits elevational movement between the bowsecuring assembly 14 and the side members 12 that carry the hullsupporting assembly 18. The extent of this pivotal movement of tongue 11 is limited by upper and lower stops 34, 35 on the side members 12.This arrangement permits the hull supporting assembly to reapportion theload during road travel by pivotal movement about the fulcrum providedby the wheel assembly 13 and accommodates resulting movement between thehull supporting assembly and the bow securing assembly withoutconcentrating the load at either the underside of the boat hull 26 or atits bow.

The solution shown in FIG. 3 can be utilized on any boat trailer,although it also is preferably used in conjunction with self-balancinghull supporting assemblies 18. In this configuration, the tongue 11 andside members 12 form a rigid framework 10, and provision is made at theupper end of mast 17 for vertical movement of the bow bracket 16 withrespect to mast l7 and tongue 11. Again, this allows for loadreapportionment during road travel by the hull supports independently ofthe bow of the boat hull.

In all three embodiments, there is a basic common support conceptinsuring reapportionment or balancing of force application along all ofthe rollers 22, 23 at any given time during road travel. This isaccomplished by mounting the balanced frames 20 or other suitable hullengaging devices about a single transverse fulcrum with some of therollers forward of the fulcrum and others rearward thereof to enable therollers to balance one another automatically and thereby reapportion theweight of the boat between them. Secondly, the member pivoted orconnected to the fulcrum is free of rigid attachment to the bow bracket16, which is fixed with respect to the front end of the boat hull. Thebow bracket 16 thus serves to fix the longitudinal position of the boathull on the trailer, but does not interfere with the balanced support ofthe boat hull itself.

In FIG. 1, the common fulcrum is at pivot connections 30, and all of therollers 22, 23 are mounted on pivotal frames so as to balance oneanother at both sides of the main fulcrum. The pivot connections 30 andwalking beams 28 supported thereby eliminate rigid connection betweenthe bow brackets 16 and the rollers 22, 23. Thus, rollers 22, 23 canreadjust their weight distribution without being hampered by thereaction of any rigid frame connection to the front of the boat hull.

In FIG. 2, the common fulcrum is provided across the wheel assembly 13.Again, rollers 22, 23 are balanced on the framework at opposite sides ofthe fulcrum and are supported by pivotal frame members in such fashionas to automatically balance each pair of rollers 22, 23, as well as tobalance one another at opposite longitudinal sides of the fulcrumprovided by wheel assembly 13. In this instance, the bow bracket 16 isfreed by the pivot connection 33 from rigid attachment to thelongitudinal support for the rollers.

In FIG. 3, the rollers 22, 23 are carried on selfbalancing individualframes, which in turn are pivotally balanced at opposite longitudinalsides of wheel assembly 13, which acts as the main fulcrum for theframework 10. In FIG. 3, the hull support independent suspension for themain roller support (framework 10) is provided by the free verticalmovement afforded to bow bracket 16 relative to mast l7.

FIRST EMBODIMENT OF THE INVENTION FIGS. 4 and 5 show in detail thestructure of the first embodiment of the invention shown schematicallyin FIG. 1. The transverse wheel assembly 13 supports the longitudinalside members 12 of the main framework 10, which converge forwardly andare rigidly secured to a longitudinal center tongue 11. The bow securingassembly is rigidly located near the forward end of tongue 11, which isprovided with a conventional hitch for attachment to a towing vehicle. Awinch 15 has a cable adapted to be secured to an eye (not shown) at thefront of a boat. The eye is drawn through the center of a V-shapedupright bow bracket 16 rigidly mounted to mast 17. The bracket 16cradles the pointed bow of the boat and prevents the boat from movinglongitudinally, while maintaining it in a centered condition at thefront end of the boat.

In the drawings there is shown a center protective roller 25 located atthe convergence of the side members 12 immediately rearward of thetongue 11. This roller 25 might be casually mistaken for a conventionalkeel roller, but it does not serve the normal function of a keel roller.A conventional keel roller along a boat trailer is used as a support fora loaded boat. The purpose of roller 25 is to prevent the forward end ofthe boat from being damaged by contact with the frame members duringloading of the boat onto the trailer. It acts as a roller guide toassist in lifting the front end of the boat over the tongue 11. When theboat hull is loaded onto the trailer, the hull is elevationally aboveroller 25 and not further supported by roller 25 in any way. The use ofkeel rollers or other fixed supports along the trailer frame is incontradiction to the basic purpose of this disclosure, namely thecomplete balancing of all vertical load support members about a commonfulcrum on the framework 10.

The illustrated trailer in FIGS. 4 and 5 is provided with three cradleframes 20, each having balanced forward rollers 22 at the center of theframe and side rollers 23 at the open rear ends of each frame 20. Theside rollers 23 are mounted to the frames 20 for pivotal movement aboutthe longitudinal center axis of the open frame legs to permit therollers to conform to the side inclined configuration of a boat hull.Each cradle frame 20 has its rollers 22, 23 movably balanced about afree transverse pivot axis by means of a cradle frame pivot connection24. In addition, where two or more cradle frames 20 are used inconjunction with one another at one side of the main framework fulcrum,it is necessary to provide intermediate longitudinal frames 27 whichinterconnect the pivot connections 24 and which in turn are pivotedabout common transverse axes by means of an intermediate pivotconnection 36.

In this embodiment, which utilizes a substantially rigid framework 10,the rollers 22, 23 are ultimately balanced about a transverse fulcrumprovided across walking beams 28 which support the entire rollerassembly. The longitudinal walking beams 28 support the rear cradleframe by its pivot connection 24. They support the two front cradleframes 20 by the pivot connections 36 of the interposed frames 27.Walking beams 28 in turn are pivotally mounted to framework 10 bycoaxial transverse pivot connections 30 between the walking beams 28 andthe respective side members 12.

In this form of the invention, all of the rollers 22, 23 are balancedabout the fulcrum of the walking beams 28, so that any load forcestransmitted from the framework 10 to walking beam 28 will beautomatically balanced between the freely pivoted rollers 22, 23 andsuch loads will not be concentrated at any particular roller area. Theexpected deflection of framework Ml will not cause undue stress on theboat hull due to the rigid connection provided at bow bracket 16, sincethe framework is isolated from rigid connection to the hull supportingassembly 18 by the common fulcrum provided at the pivot connection 30.

SECOND EMBODIMENT OF THE INVENTION The second embodiment of thisinvention is shown in detail in FIGS. 6 and 7 and is schematicallyillustrated in FIG. 2. In this form, the framework 10 includes sidemembers 12 that extend longitudinally over the wheel assembly 13. Tonguelll further includes longitudinal extensions 37 which overlap theforward ends of side members 12 and which are pivotally connectedthereto at 33. The forward ends of side members 12 have protruding upperand lower stops 34, 35 which define the respective limits of pivotalmovement of the tongue 11 relative to side members L2.

The bow securing assembly 141 is identical to that shown in FIGS. 4 and5. The rollers 22, 23 are also similarly mounted to those in FIGS. 4 and5, but the rear cradle frame 20 and the intermediate frame 27 arepivotally connected at 36 to the side members 12, rather than tolongitudinal walking beams. In this instance, the side members 12 servea function similar to that of the walking beam illustrated in FIGS. 4!and 5. Vertical deflection along the side members 112 due to road shockstransmitted through wheel assembly 13 or variations in the trailer loadwill be automatically balanced and compensated among the freely pivotedrollers 22, 23 at each longitudinal side of the fulcrum provided in theframework by the wheel assembly 13. This ability to redistribute loadalong the framework is possible due to the freedom of movement affordedbetween tongue ll and side members 12 through the pivot connection 33.

With respect to FIGS. 6 and 7, this pivoted tongue arrangement is not tobe confused with prior pivoted tongue devices which were designed tofacilitate loading or unloading of boats. As an example of such priordevices, attention is called to U.S. Pat. No. 3,057,493, granted Oct. 9,1962. The purpose of these prior pivot tongue connections was to permitthe rear end of the rigid frame to be lowered for launching or retrievalof a boat in the water. During road transport usage, the

tongue and frame are rigidly interlocked with no provision for relativefree movement between the bow support and the rollers or other membersengaging the underside of the boat. The pivot connection that existsbetween the tongue and longitudinal side members in FIGS. 6 and 7 doesnot provide sufficient freedom for pivoting the rear of the frame to besubstantially useful in launching or retrieving the boat. As notedabove, the lowering of the frame is unnecessary when the illustratedtype of roller assembly is used, since the rearmost rollers 23 on thetrailer are free to be lowered elevationally about the pivot connection24 of the cradle frame 20 supporting them.

THIRD EMBODIMENT OF THE INVENTION The third embodiment of the inventionis shown in FIGS. 8-11. The main framework 10 of the trailer issubstantially that previously discussed with respect to FIGS. 4 and 5.The illustration shows only a single cradle frame forward and rearwardof the wheel assembly 13, with their pivot connections 24 being directlyconnected to the side members 12. It is to be understood that in all ofthe embodiments, greater numbers of cradle frames 20 can be pyramided ateither side of the main fulcrum of the framework 10, which in FIGS. 8and 9 is provided between the connection of the wheel assembly 13 andthe side members 12.

Details of the third embodiment are best seen in FIGS. 10 and 11. Inthese Figures, the winch cable 38 is shown provided with an outer hook39 for attachment to the bow of a boat through the center of the bowbracket 16. This operative position of the cable 38 and hook 39 is shownin dashed lines in FIG. 11. When hook 39 is attached to the bow of aboat and the bow is pulled forwardly into engagement with bracket 16with tension on cable 38, the boat is rigidly fixed relative to thebracket 16. However, in this arrangement, the bracket 16 is verticallymovable along upright slots 40 formed through rearwardly facing ears 41at the upper end of mast 17. A transverse pivot shaft 42 on the bowbracket 16 is received through slots 40. Shaft 42 permits pivotal motionof the bow bracket 16 to conform to the bow configuration and guides thebracket 16 vertically along the length of slot 40.

While the brackets 16 can be freely supported by the pivot shaft 42alone, it is desirable that movement of the bow bracket 16 be dampened.This is preferably accomplished by interconnection of a conventionalhydraulic shock absorber assembly 43 between the bow bracket 16 and themast 17. The apparatus is preferably adjusted so as to normally locatethe pivot shaft 42 at the elevational center of slot 40, whereby the bowbracket 16 is then free to move slightly upwardly or downwardly inresponse to subsequent load variation along the trailer framework 10. Asdiscussed above, the trailer rollers 22, 23 are balanced at thelongitudinal sides of the fulcrum provided by the wheel assembly 13, andare free to compensate among themselves to accommodate reapportion thechanging load of the boat hull applied to rollers 22, 23 to road forcestransmitted through the side members 12 without hindrance of a rigidframework connection to the bow of the boat. The slots 40 provide a lostmotion connection freeing the bow of the rigid boat hull from thedeflection of the longitudinal trailer framework members.

CONCLUSION The three illustrative embodiments of this invention can becombined with one another if this is desired to further insure adequatefreedom along framework 10 to accommodate road shocks. The amount offree movement required for such compensation purposes is dictatedsomewhat by the allowable deflection along the trailer frame members. Itis to be understood that other types of balanced roller or hull engagingdevices may be substituted in place of the U-shaped cradles illustratedin these drawings and that many minor modifications might be made withrespect to the basic arrangement of components described herein. Becauseof the many possible variations, only the following claims 6 areintended to limit and define the scope of the invention set out in thisdisclosure.

Having thus described my invention, 1 claim:

1. In a boat trailer:

a wheel-supported longitudinal framework adapted to be pulled by atowing vehicle for road travel while carrying a boat in a loadedposition on the trailer;

bow securing means mounted at the forward end of the framework forattachment to the bow of a boat in a loaded position on the trailerduring road travel to prevent longitudinal motion of the loaded boatrelative to the trailer;

self-balancing hull support means operably mounted at each side of saidframework about a common fulcrum, said hull support means being free ofrigid attachment to said bow securing means;

said self-balancing hull support means being composed of spaced elementsrespectively engaged with the underside of a boat in a loaded positionon the trailer during road travel and serving as the only elevationalsupport for the boat, said elements being paired on rigid framespivotally mounted intermediate each pair of elements so as to permitmomentary reapportionment of load during road travel between the pairedelements independently of said bow securing means.

2. A boat trailer as set out in claim 1 wherein said elements arelongitudinally paired and mounted on longitudinal frames pivoted abouttransverse pivot axes located intermediate each pair of elements forbalancing of the load distribution between the paired elements about therespective axis of the frame on which they are mounted.

3. A boat trailer as set out in claim 1 wherein said elements are allmounted to longitudinal walking beams extending longitudinally along theframework and pivotally connected thereto about an axis intermediatetheir ends constituting said common fulcrum.

4. A boat trailer as set out in claim 1 further comprising:

a lost motion connection between the bow securing means and saidframework for permitting free vertical movement of the bow support meansrelative to the framework and relative to said hull support means.

5. A boat trailer as set out in claim 1 wherein the movable supportmeans comprises a vertically slotted bracket on an upright mast fixed tothe framework;

an upright bracket adapted to be secured to the bow of a boat whenloaded on the trailer;

and a transverse pivotal shaft mounting the bow bracket to the slottedbracket on the mast for limited vertical movement of the bow bracketalong said slot.

6. The apparatus as set out in claim 5 further comprising:

shock absorbing means operatively connected between the bow bracket andmast for dampening vertical movement of the bow bracket relative to themast.

7. A boat trailer as set out in claim 1 wherein the wheel-supportedframework comprises a substantially rigid main frame carrying said hullsupport means and elevationally supported by a transverse wheel assemy;

and a longitudinal tongue extending forward from the main frame, saidtongue being pivotally connected to the main frame about a transverseaxis located forwardly of the wheel assembly.

8. A boat trailer as set out in claim 1 wherein the wheel-supportedframework comprises a substantially rigid main frame carrying said hullsupport means and elevationally supported by a transverse wheel assemy;

a longitudinal tongue extending forward from the main frame, said tonguebeing pivotally connected to the frame about a transverse axis locatedforwardly of the wheel assembly;

and stop means on said frame and tongue for limiting 10 hull supportmeans;

and bow securing means freely vertically movably mounted to said mastfor attachment to the bow of a boat in a loaded position on the trailerduring road travel to prevent longitudinal motion of the loaded boatrelative to the trailer while permitting free vertical movement of saidbow securing means relative to the mast.

10. A boat trailer as set out in claim 9 further comprising:

a lost motion connection operatively interposed between said bowsecuring means and said mast permitting said free vertical movement ofsaid bow securing means relative to the mast.

11. A boat trailer as set out in claim 9 further comprising:

shock absorbing means operatively connected between the bow securingmeans and said mast for dampening vertical movement of the bow securingmeans relative to said mast.

1. In a boat trailer: a wheel-supported longitudinal framework adaptedto be pulled by a towing vehicle for road travel while carrying a boatin a loaded position on the trailer; bow securing means mounted at theforward end of the framework for attachment to the bow of a boat in aloaded position on the trailer during road travel to preventlongitudinal motion of the loaded boat relative to the trailer;self-balancing hull support means operably mounted at each side of saidframework about a common fulcrum, said hull support means being free ofrigid attachment to said bow securing means; said self-balancing hullsupport means being composed of spaced elements respectively engagedwith the underside of a boat in a loaded position on the trailer duringroad travel and serving as the only elevational support for the boat,said elements being paired on rigid frames pivotally mountedintermediate each pair of elements so as to permit momentaryreapportionment of load during road travel between the paired elementsindependently of said bow securing means.
 2. A boat trailer as set outin claim 1 wherein said elements are longitudinally paired and mountedon longitudinal frames pivoted about transverse pivot axes locatedintermediate each pair of elements for balancing of the loaddistribution between the paired elements about the respective axis ofthe frame on which they are mounted.
 3. A boat trailer as set out inclaim 1 wherein said elements are all mounted to longitudinal walkingbeams extending longitudinally along the framework and pivotallyconnected thereto about an axis intermediate their ends constitutingsaid common fulcrum.
 4. A boat trailer as set out in claim 1 furthercomprising: a lost motion connection between the bow securing means andsaid framework for permitting free vertical movement of the bow supportmeans relative to the framework and relative to said hull support means.5. A boat trailer as set out in claim 1 wherein the movable supportmeans comprises a vertically slotted bracket on an upright mast fixed tothe framework; an upright bracket adapted to be secured to the bow of aboat when loaded on the trailer; and a transverse pivotal shaft mountingthe bow bracket to the slotted bracket on the mast for limited verticalmovement of the bow bracket along said slot.
 6. The apparatus as set outin claim 5 further comprising: shock absorbing means operativelyconnected between the bow bracket and mast for dampening verticalmovement of the bow bracket relative to the mast.
 7. A boat trailer asset out in claim 1 wherein the wheel-supported framework comprises asubstantially rigid main frame carrying said hull support means andelevationally supported by a transverse wheel assembly; and alongitudinal tongue extending forward from the main frame, said tonguebeing pivotally connected to the main frame about a transverse axislocated forwardly of the wheel assembly.
 8. A boat trailer as set out inclaim 1 wherein the wheel-supported framework comprises a substantiallyrigid main frame carrying said hull support means and elevationallysupported by a transverse wheel assembly; a longitudinal tongueextending forward from the main frame, said tongue being pivotallyconnecteD to the frame about a transverse axis located forwardly of thewheel assembly; and stop means on said frame and tongue for limiting theangular extent of pivotal movement between the tongue and main frameabout said axis.
 9. In a boat trailer: a wheel-supported longitudinalframework adapted to be pulled by a towing vehicle for road travel whilecarrying a boat in a loaded position on the trailer; hull support meansmounted at each side of said framework for engagement with the undersideof a boat in a loaded position on the trailer during road travel; anupright mast on the framework forward of said hull support means; andbow securing means freely vertically movably mounted to said mast forattachment to the bow of a boat in a loaded position on the trailerduring road travel to prevent longitudinal motion of the loaded boatrelative to the trailer while permitting free vertical movement of saidbow securing means relative to the mast.
 10. A boat trailer as set outin claim 9 further comprising: a lost motion connection operativelyinterposed between said bow securing means and said mast permitting saidfree vertical movement of said bow securing means relative to the mast.11. A boat trailer as set out in claim 9 further comprising: shockabsorbing means operatively connected between the bow securing means andsaid mast for dampening vertical movement of the bow securing meansrelative to said mast.